The broad objective of the proposed research program is to investigate the role of inhibitory control mechanisms in causing both incidental and intentional forgetting in long-term memory. The importance of inhibitory processes in forgetting has been debated in psychology since the days of classical interference theory. Some investigators have attributed forgetting to passive processes such as response competition, contextual shifts, and decay. Others have emphasized active processes related to learning and attention, such as unlearning, response set suppression, and directed forgetting. In the past decade, I have developed a method that isolates the role of inhibition to forgetting. In the proposed studies, we will use this method to examine two issues: (1) the conditions under which memories might recover from suppression, and (2) the link between retrieval- inhibition and attentional control. It is suggested that, consistent with neuropsychological theories of prefrontal cortex, an attentional gating mechanism is recruited during retrieval to overcome distraction from interfering memories, and that this mechanism causes reversible suppression that underlies retrieval failures. Despite the proliferation of cognitive and neuropsychological theories asserting the importance of inhibition in achieving attentional control, the role of inhibition in intentional forgetting remains controversial. Work on directed forgetting and thought suppression offer conflicting conclusions about people's ability to exert mental control. As a third issue, an attempt will be made to relate cognitive work on inhibitory control in incidental forgetting to the strategic-use of such processes in achieving voluntary control over access to unwanted memories. A new laboratory model for studying voluntary forgetting has been developed and its relation to retrieval-based suppression will be studied. The proposed project offers an opportunity to bridge research on memory and attention with neurological theories of inhibitory control as well as with issues of clinical significance.